Steam generating apparatus



Feb. 25, 1958 v w. R. TAGGERT 4 2,824,551

I STEAM GENERATING APPARATUS Filed Jan. 4; 1954 I 3 Sheets-Sheet 1 INVENTOR Mums/e E. 746655? ORNEY Feb. 25, 1958 w. R TAGGERT STEAM GENERATING APPARATUS 3 Sheets-Sheet 3 Filed Jan. 4,- 1954 4 mvENTOii MLMER A". 7216651??- ATTORNEY trite States Patent STEAM GENERATING APPARATUS Wilmer R. Taggert, Worcester, Mass, assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Application January 4, 1954, Serial No. 402,050

Claims. (Cl. 122-459) This invention relates generally to steam generating apparatus, and more particularly to apparatus intended to be used in a steam boiler for the purification of steam.

In a steam generating apparatus the steam as it is first evolved from the water flowing in the boiler systems contains certain contaminants and impurities. It usually contains small droplets of water which, if allowed to be carried over into the superheater, may collect there forming an obstruction to the flow of steam and, in addition, by absorbing heat in vaporizing, it may upset the careful heat balance which has been evolved for the superheater. The steam also may contain quantities of chemicals such as silica which, if allowed to pass over into the turbines, will condense there, forming coatings on the turbine surfaces. While in the past these deficiencies of generated steam were relatively unimportant, the progress of the art toward higher efficiency, higher pressure, higher temperature, and greater accuracy of control, renders the removal of such foreign substances more and more important. The apparatus which has been evolved in the past for purifying steam has suffered from many disabilities. Among these are complicated and expensive construction and high resistance to flow, causing loss in boiler water flow head. These and other difiiculties experienced in the past with prior art devices have been obviated by the present invention.

It is therefore an outstanding object of the present invention to provide a steam generating apparatus providing for the purification of steam to a high degree.

It is another object of the present invention to provide an apparatus for the purification of steam which apparatus is simple and inexpensive in construction and yet suflicient and reliable in use.

It is another object of this invention to provide means whereby the incoming feed water may be used in the purification of the steam.

It is a still further object of the present invention to provide a steam purifying apparatus in which centrifugal force and condenser action are combined in the removal of foreign substances from the steam.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Figure 1 is a cross-sectional view of a portion of a steam generating apparatus embodying the principles of the present invention.

Figure 2 is a perspective view of certain important ele ments of the invention, and

Figure 3 is a cross-sectional view of a portion of a steam generating apparatus varying somewhat from the embodiment shown in Figure 1.

' external source of feed water, not shown.

7 generating apparatus.

Like reference characters denote similar parts in the several figures of the drawings.

Referring first to Figure 1, wherein is shown the general features of the invention, a steam generating unit, designated generally by the reference numeral 10, is shown as comprising a steam-and-water drum 11, downcomer tubes 12, steaming tubes 13, and steam takeoff tubes 14, a quantity of water 15 resides in the lower portion of the steam-and-water drum 11. A manhole 16 is provided at the extreme end of the steam-andwater drum 11. A primary steam separator 17 rests on a longitudinal beam 18 and extends upwardly in the drum from substantially beneath the normal water level to the lower edge of a metal bafile 19 in the upper part of the drum. The upper edge of the baffle 19 is attached to a 4 web 20 extending inwardly of the wall of the drum. A

metal baffie 21 extends generally horizontally from the web 20 and is attached to the lower edge of a dryer carton 22. The top and bottom edges of the dryer carton 22 on the side thereof away from the baffle 21 have attached thereto sheet metal walls 23 and 24 forming two sides of an elongated conduit. The lower end of the conduit 25 is flanged and these flanges are attached to a plate 26. The plate 26 extends longitudinally of the steam-and-water drum 11 from one end to the other thereof. Depending from the plate 26 are steam separator elements 27 which will be described in greater detail hereinafter. Around the lower ends of the steam separator elements 27 is attached a chamber 28 comprising a top wall 29 and a lower wall 30. Attached to and dependent from the wall 30 is a drainage trough 31 whose lower portion is connected by pipe means 32 to a conduit 33. The conduit 33 rests in a saddle 34 mounted on the upper portion of a bracket 35 which is welded or otherwise fastened to the wall of the drum 11. A feed water pipe 36 rests on a saddle 37 which is also mounted on the top of the bracket 35. A pipe 38 extends from the feed water pipe 36 to the rearward side of the container 28, while the forward side of the container 28 is attached by a pipe 39 to a feed water distributor 40 which is bolted to the forward part of the bracket 35. A pipe 41 connects the lower portion of the dryer carton 22 to the conduit 33. The feed water pipe 36 extends longitudinally of the boiler drum and is connected to an The conduit 33 also extends longitudinally of the steam-and-water drum 11 and drains externally of the drum.

Figure 2 shows the specific structure of the steam separating element 27 and its relationship to the plate 26 and the walls 29 and 30. To begin with, the element 27 is very similar to the well-known type of centrifugal separator used for removing dust and other particles from air flow and in removing flyash from the gases of a steam The element 27 comprises a central tube 42 which extends upwardly through an aperture 43 provided therefor in the plate 26. It is provided with a tapered lower end which resides in a position spaced slightly above the plane of the lower wall 30 of the container 28. The central tube 42 is circular in cross-- section throughout its length. Extending between the plate 26 and the wall 29 are inlet walls 44 and 45, each of which is a spiral in cross-sectional shape. The inner edge of each of the walls 44 and 45 resides above the edge of an aperture 46 in ,the upper wall 29. In the drawing a portion of the wall 44 has been broken away to show the relationship of the aperture 46 to the central tube 42. Extending from the wall 29 to the wall 30 is a skirt 47 which is fastened to the wall 29 and is of the same size at that point as the aperture 46. The lower portion of the skirt 47 flares outwardly, however, to meet and be fastened to the edge of an aperture 48 in the wall 30. The surface of the skirt 47 flares from top to bottom and-water drum through the steaming tubes 13 in a vaporized condition. This steam, as has been stated, contains droplets of water and certain chemical impurities which must be removed. Upon entering the steam-and-water drum the steam flows through the primary separator 17, it being prevented from flowing in any other direction by the surface of the water 15 and the baffle 19 and web 29. The steam then enters the area defined by the surface of the water 15, the wall of the steam-and-water drum 11, the upper edge of the dryer carton 22, the battle 21, the bafile 19, and the primary separator 17. The only way it can leave this space in the steatn-and-water drum is through the inlets of the steam separator elements 27. The steam enters the inlet defined by the walls 44 and 45 and is carried inwardly by the spiral surfaces thereof to the space surrounding the central tube 42. The steam is partaking of a downwardly spiralling path around the central tube 42 and passes downwardly through the space defined by the central tube 42 and the aperture 46 into the space defined by the skirt 47 and the central tube 42. Centrifugal force throws the heavier water particles outwardly against the surface of the skirt 47 and permits the lighter vapor to pass into the lower portion of the central tube 42 and upwardly therethrough. The steam passes upwardly through the central tube 42 into the conduit 25 and passes through the dryer carton 22 into the space adjacent the steam carryover tubes 14. The steam enters these tubes and is carried onward for further processing and use.

Feed water enters the apparatus through the pipe 36, passes upwardly through the pipe 38 into the container 28. The cool feed water passes through the container and out through the pipe 39 where it is discharged through the feed water distributor 40 into the water 15 in the lower portion of the drum. In passing over the outer surface of the skirt 47, however, the skirt is cooled thereby causing condensation on the inner surface of the skirt whereby chemicals and impurities are picked up and caused to flow downwardly in the water on the inner surface of the skirt 47. This water passes downwardly through the aperture 48 in the lower wall 30 of the container 28 into the drainage trough 31. Water passes from the trough 31 through the pipes 32 into the conduit 33 and from thence to the outside of the drum for discharge. Drainage from the dryer carton 22 passes downward through the pipes 41 into the conduit 33 and is also discharged.

In Figure 3 is shown a slightly modified version of the invention in which a steam-and-water drum 111 is provided with downcomer tubes 112, steaming tubes 113, and steam carryover tubes 114. A pool of water 115 resides in the lower portion of the steam-and-water drum 111 and a primary separator 117 extends from below the water level to a point in the drum above the entrances of the steaming tubes 113. The uppcr'portion of the primary separator 117 is attached to a web 120 extending from the wall of the drum and to a bafile 121 extending across the top of the drum adjacent the steam carryover tubes 114. A dryer carton 122 is fastened to the upper part of the drum and the rear edge of the baffle 121 is attached to the lower portion of the carton. A conduit 125 extends from the entrance of the dryer carton to a plate 126 from which depend steam separator elements 127. To the lower portion of the elements 127 is attached a container 128 to the lower portion of which is attached a trough 131. The lower portion of the trough 131 is attached to a pipe 132 In the which extends downwardly into a trap 133. The trap 133 has an outlet 134 whereby the drainage can be passed over into the pool of water in the lower part of the drum. A feed water pipe 136 is connected by a pipe 137 to the front of the container 128. The rear portion of the container 128 is connected by a pipe 138 to a feed water distributor 139 situated under the surface of the water in the lower portion of the boiler. The operation of this embodiment of the invention is substantially similar to that of the embodiment shown in Figure 1.

It will be understood thatin both embodiments of the invention, that many of the elements will extend completely from one end of the boiler drum to the other. Such elements are the bafile 19, the baflle 21, the dryer carton 22, the conduit walls 23 and 24, the container 28, the trough 31, as well as the feed water pipe 36 and the drainage conduit 33. At the same time a large number of certain elements will be supplied at regular intervals throughout the length of the boiler drum; for instance, the pipe 38 connecting the container 23 to the feed water pipe 36 will be duplicated at spaced intervals throughout the length of the drum. In a similar manner the pipe 39 and the feed water distributor 40 will be duplicated at frequent intervals throughout the length of the drum. This also applies to the pipe 32 joining the trough 31 to the drainage conduit 33. With regard to the steam separating elements 27, these will be spaced as closely together as possible and will extend both transversely and longitudinally of the boiler drum. In the drying it is shown that three of these elements will be spaced closely together in the transverse direction and a similar spacing will be maintained in the longitudinal direction, thus providing for a large number of these elements.

It can be seen, then, that the present invention provides a simple and etficient apparatus wherein the two previously kncwn methods for purifying steam; that is, by use of centrifugal force and by use of condensing action have been combined into a unitary construction.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the feature stated in the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A steam generating apparatus comprising a steamand-water drum, a centrifugal steam separator within the drum consisting of a skirt of circular cross-section within which foreign matter is removed from steam, liquid being thrown onto the inner surface of the skirt, a container within which the skirt resides, the container having parallel walls extending generally perpendicularly to the axis of the skirt, the ends of the skirt being attached to and in contact with the said walls of the container and the intermediate portion of the skirt being free of contact with the container, and means for passing feed water through the container and over the entire circumference of the outer surface of the skirt in heat exchange relationship to the substances within the skirt.

2. A steam generating apparatus comprising a steamand-water drum, a centrifugal steam separator within the drum consisting of a flared skirt of circular crosssection within which foreign matter is removed from steam, liquid being thrown onto the inner surface of this skirt, a container within which the skirt resides, the container having parallel walls extending generally perpendicularly to the axis of the skirt, the ends of the skirt being attached to and in contact with the said walls of the container, and the intermediate portion of the skirt being free of contact with the container, means for passing feed water through the container and over the entire circumference of the outer surface of the skirt in heat exchange relationship to the substances within the skirt, and means for draining the liquids and foreign matter which are deposited on the inner surface of the skirt.

3. A steam generating apparatus comprising a steamand-water drum, a centrifugal steam separator within the drum consisting of walls defining spiral entrance passages for the admission of impure steam, a flared skirt of circular cross-section within which foreign matter is removed from steam, a liquid being thrown onto the inner surface of the skirt, a central tube lying within the walls and skirt for the removal of purified steam, a container within which the skirt resides, the container having parallel walls extending generally perpendicularly to the axis of the skirt, the ends of the skirt being attached to and in contact with the said walls of the container, and the intermediate portion of the skirt being free of contact with the container, means of passing feed water through the container and over the entire circumference of the outer surface of the skirt in heat relationship to the substances within the skirt, and means for draining the liquids and foreign matter which are deposited on the inner surface of the skirt.

4. A steam generating apparatus comprising a steamand-water drum, 2 large number of centrifugal steam separators within the drum, each consisting of walls defining spiral entrance passages for the admission of impure steam, a flared skirt of circular cross-section within which foreign matter is removed from the steam, liquid being thrown onto the inner surface of the skirt, and a central tube lying within the walls and skirt for the removal of purified steam, a container within which the skirt resides, the container having parallel walls extending generally perpendicularly to the axis of the skirt, the ends of the skirt being attached to and in contact with the said walls of the container and the ends being free of contact with the container, means for passing feedwater through the container and over the entire circumference of the outer surface of the skirt in heat exchange relationship to the substances within the skirt, and means for draining the liquids and foreign matter which are deposited on the inner surface of the skirt.

5. A steam generating apparatus comprising a steamand-water drum, having steaming tubes and steam takeofi tubes, a large number of centrifugal steam separators within the drum, each consisting of walls defining spiral entrance passages for the admission of steam originating in the steaming tubes, at flared skirt of circular crosssection within which foreign matter is removed from the steam, liquid and foreign matter being thrown onto the inner surface of the skirt, and a central tube lying within the walls and skirt for the removal of purified steam, a closed passageway leading from the central tubes of the separators to the steam takeoff tubes, a container within which the skirt resides, the container having parallel walls extending generally perpendicularly to the axis of the skirts, the ends of the skirts being attached to and in contact with the said walls of the container and the intermediate portions of the skirt being free of contact with the container, means for passing feed water into the drum, through the container, over the entire circumference of the skirts in heat exchange relationship to the substances within the skirts, out of the container, and into the body of water in the drum, and means for draining the liquids and foreign matter which are deposited on the inner surfaces of the skirts.

References Cited in the file of this patent UNITED STATES PATENTS 2,007,966 Fletcher July 16, 1935 2,191,671 Kuhner Feb. 27, 1940 2,214,658 Brewing Sept. 10, 1940 2,428,768 Bertram Oct. 14, 1947 2,669,976 Frisch Feb. 23, 1954 2,712,929 Wilson July 12, 1955 

